1. Field of the Invention
The present invention relates generally to the manufacture of miniature electronic devices and more particularly to a method and apparatus for facilitating the attachment of electromagnetic antenna wire leads to an integrated circuit chip used in a miniature transponder device suitable for use in a wide variety of applications including implantation in a living animal. This invention further relates to a method of protecting the miniature transponder.
This application further is related to U.S. Pat. No. 5,025,550 (filed May 25, 1990), entitled "Automated Method for the Manufacture of Small Implantable Transponder Devices", assigned to the assignee of the present invention.
2. Brief Description of the Prior Art
As pointed out in the above-identified patent and copending application the disclosures of which are hereby incorporated into this application by references, miniature passive transponders of the type used for object identification, and particularly those which are implantable into living creatures, such as livestock, are very small and have inherent size restrictions that must be considered in their design and manufacture. Most such devices include a wire-wound electromagnetic antenna electrically connected to an integrated circuit which, in response to received transmitted energy obtained from the antenna, generates a response signal which is retransmitted to and through the antenna to a nearby sensor.
Heretofore, the integrated circuit was first mounted to a metal leadframe, potted, and then the potted device having leadframe leads extending therefrom was attached to the antenna by bonding the antenna wires to the leads. The necessity of providing a leadframe and assembling the semiconductor die to the leadframe not only adds to the cost of the device but also has a substantial bearing on the minimum size to which a particular device may be reduced.
In addition, it is necessary to protect the passive transponder from exterior factors such as corrosive environments and mechanically destructive impacts. This is particularly so when the transponder is small and delicate.
However, it is exactly because of the small and delicate nature of the transponders in question that adequate protection is not easy to apply. The need is therefore for a simple and efficient means for protecting the transponder which, when the protection is applied, does not harm the transponder in any way.